1. Field of the Invention
This invention relates to slide gates having gate discs which are movable on guide frames between lowered closed positions and raised open positions.
2. Description of the Prior Art
Slide gates are well known and are widely employed to control fluid flow in a variety of applications, typical examples being water and sewage treatment facilities.
Conventional slide gates are unavoidably characterized by two conflicting design considerations. On the one hand is the requirement to establish a fluid tight relationship between the frame and disc when the latter is in the closed position. To this end, flexible seals are mounted between mating surfaces on the frame and disc, and means are provided for urging the disc against and in substantially constant frictional contact with the seals.
On the other hand, however, is the requirement to minimize frictional resistance to gate movement into and out of the closed position, while also minimizing frictional wear of the seals.
In the past, those skilled in the art have deemed it necessary to strike a compromise between these conflicting requirements. Thus, frictional seating forces have been reduced in order to minimize resistance to disc movement and seal wear, but at a cost of achieving less than optimum sealing integrity.